Microstation CONNECT Drawing Seed

I have an empty DGNLIB as a container for sheet seeds. I created a new sheet model, added a border cell and then placed a drawing boundary of type DETAIL:

I opened a DGN file and used the "Named Boundary from Drawing Boundary" tool with the seed I just created:

I created the drawing from the named boundary and It appears as expected - the sheet model references the design model.

What I I can't figure out is how to define a drawing seed in the DGNLIB so that I get a drawing model referencing the named boundary and the sheet model referencing the drawing model. I know this is possible because I looked into the DrawingSeed.dgnlib which comes with the installation. I really don't understand the labyrinth of connections between the different models in that file.

Are there any resources that clearly explain how to create these types of drawing seeds? I found a long discussion and two GIF animations that shed some light on this topic: 


More info in Microstation CONNECT docs. Search for "Customized Drawing Seeds for Detail Callouts"

Still appears to be a cryptic collection of models and connections in the DrawingSeed.dgnlib. Not clear on how to create my own without editing the existing DGNLIB.